Whats the lowest cost optical flash you know of

I had a friend over last night, playing around in the new studio space. I have two of the "slave bulbs" that I use to blow out backgrounds, well I pulled the black background out and turned the bulbs to face the camera and played around with the "rock star" effect.

However my wife/assistant knocked over one of the stands and the bulb had a hard meeting with the cement floor. So I need to pick up another of those, but got to thinking maybe there is a cheaper smaller maybe not so bright alternative I could use for only this lighting effect.

So here is what I used last night
http://www.adorama.com​/LTACS.html

I know they are not expensive but add the holder to it and it starts to add up a bit. They are also just to bright for what I really want to use them for.

Suggestions on cheaper flash units

It doesnt get any cheaper than that. I suppose if you hit thrift shops and found some old flashes and bought optical slaves you might save a bit but its not an instant solution by any means.

Kinda figured as much, one stupid question, the units I have are a guide number of 26 at ISO 100. I found some real cheap (probably quality) as well as cost on ebay that I might give a shot. If the guyid number is higher then 26 at IS0 100 then it will be a brighter flash right?

Ok found the answer so never mind that questions